1. Field of the Invention
The present invention relates to a body frame structure for a working vehicle having right and left crawler running devices, with a working implement connected to the front of body frames and an engine mounted on a rear portion thereof.
2. Description of the Related Art
In a conventional body frame structure as noted above, the right and left crawler running devices have track frames secured to the body frames extending along upper positions of the crawler running devices, and the engine and an oil tank are mounted on the body frames. A working vehicle having such a frame structure is designed to have a space between the right and left crawler running devices located at a high level above the ground, to avoid the vehicle body becoming bogged down in the mud when running over a wet field or other unleveled grounds. Since the body frames lie at a high level above the ground and heavy components are mounted on the body, the vehicle has an elevated center of gravity. The elevated center of gravity brings about a serious problem of reduced running stability when such a frame structure is applied to a lawn mower which engages in a grass cutting operation on riverbeds or undulating grassy terrains. The right and left crawler running devices must be wide apart to compensate for the low running stability due to the high center of gravity, but this would result in a large overall size of the working vehicle.